//根据父节点状态设置子节点的状态
        private void SetChildNodeChecked(TreeNode parentNode)
        ...{

foreach (TreeNode node in parentNode.Nodes)
            ...{
                node.Checked = parentNode.Checked;
                if (node.Nodes.Count > 0)
                ...{
                    SetChildNodeChecked(node);
                }
            }
        }

        //根据子节点状态设置父节点的状态
        private void SetParentNodeChecked(TreeNode childNode)
        ...{
            TreeNode parentNode = childNode.Parent;
            if (!parentNode.Checked && childNode.Checked) //当子结点选中，父结点没选中时，则：选中父结点
            ...{

  parentNode.Checked = true;
            }
            else if (parentNode.Checked && !childNode.Checked) //取消选中其下全部子结点时，其父结点也取消
            ...{
                int checks = 0; //统计子结点的个数（为0时表示取消了其下全部子结点）
                foreach (TreeNode node in parentNode.Nodes)
                ...{
                    if (node.Checked)
                    ...{
                        checks++;
                        break;
                    }
                }
                if (checks == 0) //子结点都取消选中时，其父结点也取消

...{
                    parentNode.Checked = false;
                    if (!parentNode.Index.Equals(0))
                    ...{
                        SetParentNodeChecked(parentNode);
                    }
                }
            }
        }

        //节点选中状态更改
        protected void TreeNodeCheckStatusChanged(object sender, TreeNodeMouseClickEventArgs e)
        ...{
            SetChildNodeChecked(e.Node);
            // 判断是否是根节点
            if (!e.Node.Index.Equals(0))
            ...{
                SetParentNodeChecked(e.Node);

            }
        }